This invention relates in general to automatic temperature control systems for diver heating systems and, in particular to a diver heating system incorporating thermally controlled gas flow valves for controlling the flow of oxygen to a combustion process that heats water being circulated through the diver's clothing. More particularly, this invention relates to a gas flow valve and a gas shut-off valve in which the operating state of the valves is controlled by the temperature of a fluid.
In order to permit a diver to work for prolonged periods immersed in cold water, diving suits have internal circulation passages through which a heated fluid is circulated. One method of heating this circulating fluid involves the controlled combustion of a metal such as magnesium in an oxygen atmosphere with the combustion rate determined by the rate of oxygen flow to the process. A previous method of controlling the gas flow to the reaction process used a rubber sleeve over a closed-ended tube having radial holes. Pressurized oxygen flowed into the tube, through the holes, along the sleeve and out another tube. A thermo wax was disposed surrounding the inner tube within a larger outer tube. The thermo wax was in thermal contact with the heated fluid through the outer tube. As the temperature of the circulating fluid increased, the thermo wax would expand and compress the sleeve against the radial holes in the inner tube. This restricted gas flow through the device. The restricted gas flow slowed the reaction and gradually reduced the heated fluid temperature. As the fluid temperature dropped, the wax would contract and allow gas to flow with less restriction through the radial holes. This method for controlling gas flow to the reaction process, although automatic, did not permit adjustment of the control temperature nor provide precise temperature regulation.